The invention relates to a device for endless coiling of strip material to form a plurality of coils, preferably of hot-rolled sheet metal in the hot state, onto a one coiler drum from two coiler drums, which are arranged at a constant distance on a supporting fixture and can each be rotated by means of a dedicated drive fixture to move synchronously, but alternately, from an initial coiling position to a coil removal position, and to an associated method.
Casting of steel using the continuous casting process followed by on-line rolling results in the formation of an endless strip, the length of which is generally such that it is no longer possible for this endless strip to be wound into a single coil. For example, if a casting ladle with a capacity of 95 t is used for casting, the strip which is formed has to be wound into at least three coils.
When coiling an endless strip in a plurality of coils, it is necessary for the strip to be cut in accordance with the permissible coil weight and to be coiled alternately on two or more coiling devices to form coils. In this context, it is known for the endless strip to be cut after finish coiling of a first coil and for the new strip start formed in this way to be guided via guide devices and switches to a second coiling device which is still empty. At high strip speeds, a very complicated mechanism is required to ensure safe guidance of the strip.
To avoid such complex strip guidance systems, it is known (EP 0,773,178 A1 and EP 0,406,249 B1) to use so-called carousel coiling, in which two coiler drums are arranged at the end sides of a vertical support plate. As a result of rotation of the support plate, the axis of rotation of which is horizontal, the coiler drums are moved from a coiling position into a release position. If, in such arrangements, the rotary drive for the coiler drums is arranged in a stationary position, an extremely complex mechanical drive fixture is requited to drive the coiler drums, which adopt different three-dimensional positions.
According to EP 0 773 178 A1 each drum has its own drive, which is arranged on a support plate or a parallel further support plate which rotates synchronously with the support plate. However, this arrangement has the drawback that the electrical connections for the drive motors are difficult to establish; owing to the high weight of the coils, drive powers of up to 1000 kW are required. In accordance with the latest prior art, the electrical energy has to be transmitted via sliding contacts, since it is necessary for the carousel coiler to rotate through over 360xc2x0. Transmitting electrical energy to this extent is not only complex, but often also causes faults which have a particularly adverse effect on endless coiling. It is then necessary for the rolling mill to be shut down, which of course considerably impairs the quality of the strip.
The object of the invention is to avoid these drawbacks and difficulties and to provide a device of the type described in the introduction which enables strip material to be coiled endlessly in a plurality of coils in a simple manner and without high mechanical outlay. Still another object of the invention is to provide a device in which the electric power can be easily transmitted. Still a further object of the invention is to provide a device having a high level of operating reliability.
According to the invention, these objects are achieved by the fact that the coiler drums can each be moved from an initial coiling position in different directions to a respective finish coiling position.
The finish coiling positions are at a distance from both the initial coiling position and the coil removal position and are arranged in such a manner that, when one coil is in the finish coiling position, the other is in the initial coiling position. With such a design of the device, it is possible to move the drums from the initial coiling position into a finish coiling position and then into a coil removal position using reciprocating movement of the drums, so that the electrical energy can be supplied to the drive motors of the drums via movable cables. In addition, the coil removal position can be optimally located, so that the initial coiling position for the drum from which the coil which has been finish-coiled has just been removed can be reached in a very short time, if the coil removal position is not in any case identical to the initial coiling position. device, it is possible to move the drums from the initial coiling position into a finish coiling position and then into a coil removal position using reciprocating movement of the drums, so that the electrical energy can be supplied to the drive motors of the drums via movable cables. In addition, the coil removal position can be optimally located, so that the initial coiling position for the drum from which the coil which has been finish-coiled has just been removed can be reached in a very short time, if the coil removal position is not in any case identical to the initial coiling position.
Preferably, the initial coiling positions are identical for both coiler drums, i.e. there is only a single initial coiling position, making the device according to the invention particularly easy to operate.
According to a preferred embodiment, the coil removal positions are also identical for both coiler drums, i.e. there is also only a single coil removal position, so that a single coil removal device, which in this case may be arranged in a stationary position, will be sufficient.
A particularly simple design of the device is produced if the initial coiling positions are identical to the coil removal positions. A preferred variant is characterized in that only a single initial coiling position and a single, identical coil removal position is provided for both coiler drums.
In terms of motion engineering, a particularly simple solution for the device according to the invention is produced if both the finish coiling positions and the initial coiling positions and the coil removal positions lie in a single plane.
In this case, the plane is preferably arranged at an angle to the horizontal, the plane expediently including an angle of between 30 and 60xc2x0, preferably an angle of between 40 and 45xc2x0, with the horizontal.
A particularly simple operating method or design of the device is produced if for each of the coiler drums the initial coiling position is located centrally between the finish coiling positions and is identical to the coil removal position, a coil removal device being provided vertically underneath the initial coiling position and the coil removal position.
A preferred variant is characterized in that the coiler drums are arranged at an axial distance from one another on a supporting frame, which can be adjusted by means of a movement fixture, taking the coiler drums from an initial coiling position to a finish coiling position or to a coil removal position.
Preferably, a dedicated drive fixture and dedicated pressure rollers are provided on the supporting frame for each coiler drum.
If the coiler drums are designed as expanding mandrels, it is advantageous to provide an auxiliary initial coiling device, in which case advantageously the auxiliary initial coiling device, which is designed, for example, as a roll cage coiler or as a belt or chain coiler, can be moved, by means of an adjustment device, into an assist position, in which it engages around a coiler drum, and into a waiting position, which is at a distance from the assist position, preferably below or behind the plane formed by the supporting frame, and vice versa.
A method according to the invention for the endless coiling of strip material to form a plurality of coils, preferably of hot-rolled sheet metal in the hot state, onto two coiler drums which can each be driven by means of a dedicated drive, the coiler drums being moved synchronously, but alternately, in opposite directions between an initial coiling position and a coil removal position, is characterized in that a first coiler drum is moved from the initial coiling position into an associated, dedicated finish coiling position as soon as the initial coiling on the first coiler drum has taken place, after which a coil undergoes finish coiling, the strip material is cut and a new strip start which is formed in this way is guided to the second coiler drum, which in the meantime has been moved into the initial coiling position, where initial coiling of the strip material takes place, whereupon the second coiler drum, supporting the coil which has just undergone initial coiling, is moved into a dedicated finish coiling position, which differs from the finish coiling position assigned to the first coiler drum, where the coil undergoes finish coiling, during which period the coil which has previously undergone finish coiling on the first coiler drum is moved to the coil removal position, where it is removed, and the coiler drum which is then empty is moved into an initial coiling position, and in that the cycle is then repeated.